The transmission shop dropped the clutch this morning and found some very interesting things. At some point in the recent past, a new clutch was put in with new freeze plugs, pilot bearing, and (possibly) a flywheel. But the crank bolts weren’t sealed and apparently backed themselves out, smoking the clutch surface and possibly the flywheel. Jack sent me photos of the inside of the case and all of the parts, and it’s just puzzling. He gave me a disc diameter and a spline count, and I jumped on RockAuto to find the right replacement. Within five minutes I’d ordered it over the phone, to be delivered Wednesday.
I’m so glad I didn’t continue trying to mess with it in the driveway; I never would have sorted this out myself.